Semester ending, the first sweet Saturday in April at the University of Northern Colorado. Many underage drinkers. Revelers burned sofas in the street, a television set, junk. A couple of hundred kids. Then police came.

Officers estimated 1,000 people were at various street parties the night of April 28 in Greeley, Colo. Rioters hurled rocks and bottles at police, who responded with tear gas and rubber bullets.

Mr. Fisher's roommate, Kurt Pydyszewski, was among 30 arrested. Faced with arson and rioting charges, the 20-year-old sophomore went home to Denver, put a gun to his head and killed himself. Friends said he feared prison.

Mr. Fisher had watched the party from his front porch. The fire was fun at first. It was cool, he said. Hardly a riot, he insisted. Nobody jumping on cars, breaking windows. Nobody's house got looted.

Events last month in Greeley took a tragic turn. But in other respects  the big crowds just off campus, the underage drinking, the bon fires, the many arrests  the parties at Northern Colorado were part of a pattern repeating itself lately in college towns nationwide.

Lacking any systematic study, observers are reluctant to call it a trend; overindulgent and rowdy college students are not new. But the rising intensity and destruction are grabbing attention.

The spark may be anything from fine weather to end-of-school euphoria, Halloween, sports wins  or losses. College students have waged time-change riots when bars shut early for daylight saving.

Administrators are baffled.

We are frustrated and puzzled about what to do, said Carol Cartwright, president of Kent State University. The first weekend in May, block parties near the Ohio campus on two successive nights led to 77 arrests.

The first night, revelers threw stones and bottles at riot-gear clad police, who fired plastic pellets to disperse a crowd of nearly 1,000. The next evening, some 2,000 people filled a parking lot and apartments for a barbecue where a couch and a car were set ablaze.

At Ohio State University last month, students and police clashed two weekends in a row at off-campus parties. The next weekend, police arrested 137 people for alcohol-related offenses and cited 15 stores for selling alcohol to people under 21.

Hordes of drunken youngsters starting fires and battling police might be treated differently in another setting. But authorities may give some latitude in a college town.

I don't think we take a hands-off approach because our clientele are college students from affluent families, said Deputy Police Chief Rene Kelley in Durham, N.H., where half the town's 24,000 residents are University of New Hampshire students.

But we also live with the reality that this is a college community, and part of the college experience is engaging in high-risk behavior.

It's all familiar to Professor Jerry Lewis, a Kent State sociologist and expert on crowds.

The wild partiers are students  chiefly young white males  simply letting go, Mr. Lewis said. Contrary to the image of the freewheeling college student, many feel oppressed by studies and deadlines.

Being a rioter gives them permission to do what they can't do normally, Mr. Lewis said. We always say college students have freedom; they don't.